240 likes | 413 Views
United Nations Economic Commission for Europe. Monitoring of Radiologically Contaminated Scrap Metal The United States Experience April 5-7, 2004 Geneva, Switzerland Prepared by Deborah Kopsick, US EPA Ray Turner, David J. Joseph Company S.Y. Chen, Argonne National Laboratory.
E N D
United NationsEconomic Commission for Europe Monitoring of Radiologically Contaminated Scrap Metal The United States Experience April 5-7, 2004 Geneva, Switzerland Prepared by Deborah Kopsick, US EPA Ray Turner, David J. Joseph Company S.Y. Chen, Argonne National Laboratory
Why are We Here? • Increased concerns among governments over radioactive materials in scrap metal. • Hundreds of thousands of orphaned sources still unaccounted for worldwide. • Increased scrap shipments across international boundaries.
Recent Developments Prompting Action • Growing awareness of the potential for accidents occurring (Better reporting? More demolition? Aging industry?). • Some accidents have serious, even fatal, consequences, often to the public. • Growing awareness of problems with “orphan sources.” • Potential exists for orphan sources to become Radiation Dispersal Devices (RDDs). • Increase in international shipments of scrap metal.
The Initiative Focuses on Protecting Commerce But Also Overlaps with Other Existing Initiatives
Overview of U.S. Radiation Control Border Programs • The U.S. has taken a very aggressive approach to monitoring for unwanted radioactive material in imported goods. • By September 2004, 90% of all seaports will have radiation monitoring for all incoming container cargo: • 361 sea and river ports, • Several million cargo containers a year, • Previously only 3% were monitored by hand. • 248 portal monitors in use at land border crossings with Canada and Mexico. • Currently, scrap metal is only monitored at 3 seaports.
Goals for This Meeting • Share information on USEPA/US Customs Seaport Monitoring Pilot Project. • Learn from other nations, experiences in scrap metal radiation monitoring. • Discuss issues identified in UNECE Questionnaire, identifying areas of international consensus, as well as areas where additional examination is necessary. • Is it possible to develop an internationally acceptable scrap metal radiation monitoring and response protocol?
US EPA/Customs Seaport Pilot Project • Established before 9/11 attacks to monitor scrap metal imported into the U.S. for radioactive material. • Pilot established in New Orleans, Louisiana, U.S. in August 2001, later expanded to Charleston, South Carolina. • Pilot project focused on monitoring imported sea-going bulk cargoes of scrap metals. • More than 2,000,000 metric tons of scrap metal monitored to date.
Pilot Objective • Study the issue of importing scrap metal inadvertently contaminated with radiologically contaminated materials • How much radioactive material is entering the scrap metal supply from imported sources? • How effective are available monitoring technologies suitable to be used during the ship off-loading process? • Can a protocol be developed that would allow on-site dock personnel to operate the monitoring equipment?
Anticipated Project Outcomes • Collect data to understand the scope of how much unwanted radioactive material is entering the U.S. through imported scrap metal. • Initiate development of U.S. monitoring standards modeled after accepted international monitoring protocols.
Operations Protocol Shipment of scrap metal enters the port for offloading Scrap metal is off-loaded from ship with grapples equipped with radiation detectors USEPA representativewith hand-held radiationdetector surveyssuspect material Segregatesuspectmaterial Yes Radiationalarm occurs No Shipmentproceeds Notify the State, whichwill follow its normalnotification andresponse procedures Find sourceand isolate USEPAcollects data Rest ofshipment proceeds Buyer works with sellerto dispose of contaminatedmaterial with state andfederal oversight
Grapple Monitor Testing Protocol • Oak Ridge National Laboratory (ORNL) • Review and analyze field observed problems • Develop an effective routine performance range • Develop a field testing protocol • Quality Control Tracking • Radiation sensitivity estimation • Theoretical, laboratory, and field technical support Chiaro, Peter, ORNL, 2004
Results • The monitors, procedures, and protocols used provide a framework for future efforts to detect, identify, and isolate radioactive materials in scrap metal. • The monitors can be operated and maintained by on-site dock personnel. • The detection system provides assurance against the importing of contaminated scrap metal, based on field, laboratory, and theoretical testing.
Accomplishments • 10 Detection systems installed and tested • Equipment • Protocols • Training • Monitored more than 300,000 tons of scrap thus far in Darrow, Louisiana • Data collected • System worked/system issues identified and corrected • System operating procedures validated • Modeled detection capabilities • Expanded to Charleston, South Carolina, in 2003 • Monitored more than 1.7 million tons in Charleston in 12 months
Next Steps for the Pilot Study • Continue to collect data and monitor ports for imported radioactive metals. • Expect to expand to other seaports. • Work with the international community to collect data to determine the extent that importing contaminated metals is a problem and steps other countries are taking to prevent this problem. • Determine need for additional EPA action.
Issues with Land Scrap Metal Monitoring Systems • Different types of detectors will allow detection of different types of radiation. • The location of the detector is critical to successful detection. • The location of the source within the scrap load (amount of shielding) will determine if it can be detected.
Radiation Monitors May Be Limited in Their Capabilities Even the best systems do not always detect a source that could cause a multimillion dollar cleanup! Sodium Iodide: Does not detect neutrons • High “stopping power” • Good for handheld devices • Large area detectors impractical; costly Plastic Scintillator: Does detect neutrons • Moderate “stopping power” • Good for hand-held devices and fixed monitors • Large area detectors practical
Self-Shielding of Scrap Hinders Detection Capability Vehicle Count Rate for a Truck Shipment
The Detection Capability Increases with Large Area Detectors Small Areas Detector misses radiation Truck filled with scrap Large area detector picks up radiation Typically have 18” to 24” spread Lamastra, A. 2003
1996 SMA Test (Side Detectors) Shows Detection Is Highly Dependent on Scrap Thickness Detection category Easy ( 6” Shred) Moderate (7”-13” Shred) Hard (14”-16” Shred) Very Hard (17”-19” Shred) Extremely Hard (20”-22” Shred) Almost Impossible ( > 22” Shred) Overall percentage 100% 100% 84% 69% 6% 0% Lamastra, A, 1998
Location and Type of Monitoring Can Also Affect Detectability • Monitoring location will impact system sensitivity, and the production and ease of returning scrap to the owner. • Scale or plant entrance fixed monitors • Conveyor monitors • Charge bucket monitors • Grapple monitors • Dust monitors (too late to prevent) • The smaller the amount of scrap monitored, the better the chances of detecting the radiation source.
Waste Disposition: A US EPA Source Roundup Program Offers A Viable Option • Round-up of known discreet orphan sources in 1 state. • 36 - 137Cesium sources were returned to the manufacturer. • Successful, inexpensive pilot, which led to nationwide, federally funded orphan source program available to states.
Path Forward • International trade can bring opportunities as well as problems. • Effective regulations and guidance are needed to ensure that the public and industry are protected and that international commerce is not adversely affected. • Monitoring systems and protocols need to be established, communicated, and implemented internationally.
United States Contacts International contact: • Debbie Kopsick Kopsick.deborah@epa.gov 202-343-9238 Consultants: • S.Y. Chen, Ph.D. SYCHEN@anl.gov 630-252-7695 • Ray Turner RT@rmrecycling.com 513-703-0981